Amp Camp amps

[PWR RYD]

Great looking amps djg! Unfortunately Tubedepot no longer sells the K12G tube amp kits.... I built one and did a few upgrades and it is a truly great amp to listen to if you only need 8 wpc. Tubedepot still has other tube amp kits available but I haven't read any great reviews about those. The K12G amp kit at $179 was a steal! Now if I could only get that amp back from my friend that borrowed it....

[djg]

Thank you.

[djg]

Beauty shots.

[silverD]

I was wondering if you were going to use the stickers...

[djg]

So I can tell them apart.

[Steve Lee]

Nice!

How do they sound?

[djg]

In bridged pair in a 2.1 nearfield setup above 80 HZ into 8 ohm Continuums, they sound pretty good. Tonight or tomorrow I'll set them up in the living room into the 4 ohm (or thereabouts) full range Zingers, bridged pair and single. Then we'll see.

[djg]

So, I can't recommend these for anything but nearfield 2.1 IME. Perhaps with some DIYaudio type high efficiency speakers they might give adequate oomph. Android tablet through BT and a passive volume control to one amp not adequate, through two OK if you want to show people your homebuilt amps. This is into Wolf's Zingers.

Again, my nearfield 2.1 Continuum bridged pair sound is very pleasant. These are fun to build, just don't expect too much. An SMSL chip amp gives better performance.

[Steve Lee]

Thanks for the honest review and direction.

[djg]

I'll hook just one up nearfield 2.1 soon. It requires crawling and cursing under the PC desk.

[a4eaudio]

An SMSL chip amp gives better performance.]

As others said, thanks for the honest review. Does the chip amp give better performance simply sure to the extra power? Particularly, if you were running them both at a low level like 2-4 watts is there a difference in sound quality?

[djg]

The chip amp is cheaper and easier for more power.
I would have to do a side to side to answer your second question.

[djg]

So, I did the no crawl no curse option, I hooked the Amp Camp Amp up in 2.0 mode. Bypassed the sub. Many people would run it this way. I used my S2000 MTMs, rumored to be 4 ohm 92 db sensitive speakers.

While I could turn it up to 100 on the sound level from the PC and not wince, the sound is quite acceptable. Loud enough for a lot of people. Bass is pretty good. I was surprised after the single amp/Zinger experience.

I think a single Amp Camp Amp in 2.0 nearfield with sensitive speakers is feasible.

Going back to the 8 ohm less sensitive Continuums, noticeably lower volume, borderline. If you want to rock out at your desk, this ain't the ticket.

[blue934]

Beautiful Harbeth styled Continuums!!!

[djg]

http://techtalk.parts-express.com/fo...ontinuum-build

[djg]

Final thoughts.

A complete DIYaudio Amp Camp Amp kit is $327. That's really expensive. That's a $127 parts kit, a $50 Meanwell 24V 5A brick, and a nice Italian Aluminum Chassis, all drilled, tapped and labeled for $150.
I bought the parts kits, they are very well sorted and packed. Absolutely perfect. I bought PE bricks for $30 on sale. I found a $70 Chinese WA92 spec chassis. This chassis really makes this build. It is hard anodized brushed black aluminum with a 5/16" thick brushed aluminum front. The top, bottom, and back are 3/32" thick.

The chassis is just high enough for the PCBs. Actually, slight size variations in the PCBs had them sticking out a hair. I could have sanded them, but what I did was space the top and bottom with washers under the six mounting screws. About 1/32". I'm sure this cuts heat transfer to them from the heat sinks. The heat sinks and the front panel get very hot. Top and bottom just hot. I just siliconed the feet on.

The red LEDs in the silver panel look really cool. Really.

I was down on these after the Zingers. Now, I think one or two in a 2.0 or 2.1 desktop setup is workable. Just depends.

Right now, Simon and Garfunkel Sounds of Silence without the rock add on. Very nice experience. Sorry no squiggles or figures, just anecdotal.

[Prana Ferox]

Thanks for the review. Needing projects to maintain soldering proficiency, I looked for DIY amp kits a while back and only found these and a bunch of tube kits, usually even less watts for more money. I ended up doing the pay-it-forward Audiosource AMP100 mods for considerably less.

It's a shame there aren't more mainstream, budget amp kits, preferably with a gain control option. Then again, maybe there's not a lot of appetite for the liability of having newbies assemble power electronics.

[djg]

This amp avoided AC house current by using a power brick. Expensive for what you get.

[invaderzim]

I had been starting to think my impression of the ACA must have been completely wrong; given all the reviews that say how amazing they are. I built a single stereo one several years back and kept trying to use it but would always end up switching to a different amp. I finally gave up and scrapped it to use the heatsinks for other projects.

There was a post I saw from Nelson Pass where he said that the amp wasn't designed to be the best sounding amp but to be easy enough to assemble in a day and use a simple and safe power supply. It was, after all, created for 'amp camp' where people came and built the amp in one afternoon. Somewhere along the lines it developed a reputation due to his involvement that has made its performance almost mythical.

If someone already has heatsinks and just builds the boards as a rough project it isn't too expensive and could be fun but for a similar price to the full ACA kit the Akitika GT-102 was way more enjoyable to listen to. There is no getting to tell people that you built a 'Nelson Pass' amp but I spent way more time listening to music with the Akitika than I ever expected; I just didn't want to turn it off.

Every time I see another youtube infomercial host gushing about how amazing the amp is I wonder what I was missing. But I don't think I was missing anything. It wasn't like I turned it on and went "that sounds terrible". I turned it on, started listening to music and every time after just a little while I'd go do something else. The music just never pulled me in with it; no matter which room or system I put it in. There are so many other amps that when I'm listening to them I end up needing to go do something else but I keep telling myself 'just one more song'.

[djg]

I agree pretty much. I'm still on the fence about selling these. They came out really nice in the WA92 case. I could probably get some of my money back. After the living room listening I was ready to dump them. Nearfield I like them.

I've built other amps Classdaudio kits were almost too easy. The Dynakitparts ST-35 tube amp kit was fun and produced an exact copy of a well known vintage amp. I also built a tube preamp. Fun, but both of these were expensive as you state.

It's cheaper to buy a finished amp.

[djg]

ACA/SMSL SA-50 showdown, later today. I'll throw in the ST-35 too, WTH.

[invaderzim]

That is the one plus with a known design and a quality finished product, they are sellable. My work is a bit more rough around the edges so resale is harder.

The amp wasn't terrible and I'm a big fan of Mr Pass but it has always baffled me how it receives such glowing reviews when I didn't see it as being that enjoyable. At one point I was actually tempted to build another just to see what I'd missed.

Do you use a preamp with the ACA? I've wondered if it would perform better with a stronger signal fed to it.

[djg]

Audio Science Review trashed the ACA. ASR members piled on in the thread. The ACA in nearfield is fed by a Schiit DAC through my Dayton SPA250DSP subwoofer, via XLR, or 2.0 via RCA.. The living room test was an Android tablet through a Bluetooth receiver and passive volume control. My only preamp is a Vacuum Tube Audio SP-8.

DIYaudio is well, DIYaudio.

[invaderzim]

I saw the thread there. Some seem to get joy out of trashing things. I don't think it is terrible; it has just taken on a legend that exceeds its reality.

[djg]

Well ASR is right that the ACA output is quite low, and the ASR crowd would rather look at squiggles than listen to music.

THe ACA is a class project as you say. I'm proud of my work but they are not legend material.

[djg]

Anticlimactic.
The SMSL is loudest, but you don't want to turn it past 12 o'clock. The ST-35 is not as loud, the ACA has the least oomph. You all probably knew that already.
Quality? I'm going to leave the ST-35 plugged in for a while, Continuums no sub.
I'll probably put the ACAs on craigslist. They have name recognition and curb appeal. The twin cities is crawling with hipster audiophiles. I like them, they sound OK, I just have so much stuff they'll sit under the bed. I can bring joy to an enthusiast who can't build one (or two) themselves.

[ugly woofer]

If you want a diy Nelson Pass amp, I would suggest a First Watt. They're not as cheap, but the sound quality is pretty darn good.

[ugly woofer]

You could keep the chassis and use a 3886 based design. Just a thought.

[djg]

I've worked through the Class A amp bug, I may build a tube amp sometime. Like I need one.